It is becoming more common to use electrosurgical and/or thermal devices during surgery because such devices may provide benefits over traditional medical devices. For example, electrosurgical and/or thermal devices may allow a surgeon to make precise incisions with limited blood loss. Because of their advantages, electrosurgical and/or thermal devices may be used in dermatological, gynecological, cardiac, plastic, ocular, spine, ENT, maxillofacial, orthopedic, urological, neurological and general surgical procedures as well as certain dental procedures, just to name a few.
Surgery generally involves cutting, repairing and/or removing tissue or other materials. Electrosurgical and/or thermal instruments may be used to perform each of these procedures by using the electrosurgical and/or thermal instrument to heat the tissue or other material to a desired temperature. Tissue may react differently, however, at different temperatures. If the temperature of the electrosurgical and/or thermal instrument is not properly controlled, then undesired results may occur which may lead to an adverse outcome for the patient.
Furthermore, a surgeon may be required to use an electrosurgical and/or thermal instrument for a prolonged period of time during a given procedure. During this time the instrument may be intermittently moved in and out of contact with a portion of the patient's body. This can lead to problems both with heat management within the device itself as well as heat management of the heated surgical tip of the instrument. When the instrument is not in contact with a portion of the patient's tissue, body fluid, etc., it is held in the air above the patient's body, and it may be important to limit the power delivered to the instrument to minimize transfer of heat to areas of the instrument where heat is unwanted or even detrimental. For example, if heat transfer to a portion of the electrosurgical and/or thermal instrument which is gripped by the surgeon is not properly controlled, the device may become too hot and the surgeon may not be able to handle the instrument for the time necessary to complete the procedure.
Additionally, if the active portion of the electrosurgical and/or thermal instrument, such as a thermal element, is overheated or exposed to excessive thermal stress, the thermal element may be damaged.
Thus there is a need for improved system and method of controlling the delivery of power from an energy source to an electrosurgical and/or thermal surgical instrument to prevent overheating of the instrument and/or the heated surgical tip.